They call them ‘stars’ for a reason. Like those ephemeral heavenly bodies, they can light up even the dimmest scenario - and for the most part, the new action thriller Knight and Day is pretty faint indeed. The story makes little or no sense, the characters come complete with tiny deviations on their otherwise cardboard cut-out facades, and the overall feeling is about as preprogrammed and corporate as cinematic creativity can get. But thanks to the deft hand of director James Mangold behind the lens and the two incredible actors - Tom Cruise and Cameron Diaz - he has in front, what should have been slight comes across as a sturdy mainstream summer entertainment. It’s not rocket science, but it doesn’t crash and burn either.

Roy Miller (Cruise) is a secret agent accused of turning on his country, stealing a valuable new energy technology, and going rogue. June Havens (Diaz) can’t seem to find a good man while restoring classic cars for a living. Both end up on a fateful flight from Wichita, KS back to Boston, MA. She thinks he’s attractive. He thinks she’s cute - but must fight off a plane full of assassins during the meet-cute. Soon, the couple are embroiled in an international incident involving an arms dealer, a determined FBI agent (Peter Sarsgaard), his no nonsense boss (Viola Davis) and a prized science geek named Simon Feck (Paul Dano) who holds the key to the endless power source. As they find themselves in one coincidental clash after another, June starts to believe that Roy is using her as decoy to avoid suspicion. When it looks like our lead has indeed switched sides, it is up to our heroine to take matters into her own hands.

There are definitely times when Knight and Day feels ludicrously out of control. From the very moment Cruise starts busting heads on a doomed cross country flight, we are asked to suspend a mighty big wad of outrageous disbelief - and it’s a whopper. From then on, we have roof chases, narrative conveniences, motorcycle fu, enough perfect teeth smiles to sell a billion dental plans, and continuing proof why Hollywood continues to hire Cruise and Diaz for their leading roles. He’s all magnetic effervescence, virility and power without being overtly macho. It’s the kind of non-threatening champion he’s relied on his entire career. She is showing a bit of her age, but still comes across as the attractive babe-defyting tom boy you’d want to have a beer - or a weekend in the tropics - with. Together, they form an almost irresistible combination that saves some rather sloppy plotting.

Indeed, the MacGuffin mystery at the center of Knight and Day is virtually unimportant. We are told of the battery-like device’s abilities in an off-hand conversation that feels like two disinterested pals discussing an order of onion rings. Then it disappears for most of the second act, only to play like a punchline in the third. Similarly, the truth of Cruise’s character (whether he’s a turncoat or not) is never really explored. It’s mentioned one time like a veiled threat. From then on, his loyalties are more or less a preset given. Certainly the script tries to twist things up just a little, keeping the identity of the real traitor under wraps until the last minute. But it’s all a ruse, an unnecessary nod to storytelling complexities that Knight and Day neither strives for, readily achieves, or even acknowledges.

Thankfully, with Mangold in charge, the adrenalized spectacle breeze by. Though you’d never know it from his oeuvre (the terrific 3:10 to Yuma remake aside), the director is rather adept at over the top action. The plane fight is fun, as is a city street escape which sees Cruise launch himself from a motorcycle onto a moving car. Sure, the “unconscious” sequences where drugged up characters can barely see the epic pandemonium going on around them is aggravating, and there are too many leaps of illogic to overcome. But Cruise and Diaz can make you believe almost anything, and it is there job here to carry us across the troubling bits. Even toward the end when greenscreen threatens to completely undermine the level of believability, one grin from these amiable A-listers and we’ll buy almost anything. Almost.

Of course, had we a stronger set of supporting players, there’d be another element to guide our misgivings. Sadly, Sarsgaard and Davis are like unnecessary cogs in a borderline useless machine. We need them to provide exposition and a bit of drama, but the movie probably would have worked fine without them. Similarly, Paul Dano does a bang up job as a socially inert uber geek, but he’s on screen for such a short period of time, and given so little to do when he is, that he becomes a kind of in-joke: important to the plot, almost worthless to our level of involvement and enjoyment. Thankfully, Cruise and Diaz can carry this movie on their own well proportioned shoulders. Their chemistry is palpable and their sense of similar purpose apparent.

Still, it may be an uphill battle for Knight and Day to find an accepting audience. It is not aimed at ADD-addled adolescents (though the short attention span teen will clearly love the nonstop movement of the mayhem) and the die-hard genre buff will see through this piffle like the creative cotton candy it is. But for an older audience that misses the days of fame and fashion, of good looking leading men mixing it up with equally engaging gals, this movie is nothing short of manna. Like the Tinseltown’s picturesque past where films could get by on being escapist fun only, Knight and Day uses the built-in bravado of its actors to salvage sensibility and sensationalism out of the senseless. It might not be everyone’s high octane cup of chaos, but with the veritable dearth of amusement escaping from the current crop of Summer specials, it sure is a lot of fun.

The Wolverine is a waste of time from the first shot to the rushed, slipshod finale. It feels forced, sledgehammering you with how deep and important it thinks it is while never really explaining how, or why.